Some investors play both sides of the game to make money without any other motives other than making money. I know several people who trade on a stock when it is going up to make money. They need to have a stock that has the volume being traded, and a pattern of dropping a bit and then going back up. Easy enough to do. I made a pile of money when HPQ was going up. I bought when it dropped a bit, but then sold when it went back up. 10,000 shares with a $.02 rise gives a gain of $200 less expenses. When HPQ was going up the swing of two cents to ten cents would happen several times a day. So cha ching.

Shorters likely look at all the sme patterns. These would happen more often on the venture exchange especially in the mining and technology, and R&D stocks. So I don't think anyone is doing anything out of the ordinary to keep HPQ down, it's just the pattern of what a developing company goes through.

So no bogy man, just traders playing both sides, and with todays economy the short side seems to make them more money. As for myself I don't know enough about how to short, plus don't believe in putting bets on something that I believe in to go down. But many play both sides cause they are in it to make money.